Class ExpressionDataPoint

src/query/expression/ExpressionDataPoint.java:33–258

Contains the information for a series that has been processed through an expression iterator. Each time a metric data point series set is added we add the metric and compute the tag sets. As the iterator progresses, it will call into the #reset methods. @since 2.3

 * @since 2.3
 */
public class ExpressionDataPoint implements DataPoint {

  /** A list of metric UIDs wrapped up into this expression result */
  private final ByteSet metric_uids;
  
  /** The list of tag key/value pairs common to all series in this expression */
  private final ByteMap<byte[]> tags;
  
  /** The list of aggregated tag keys common to all series in this expression */
  private final ByteSet aggregated_tags;
  
  /** The list of TSUIDs from all series in this expression */
  private final Set<String> tsuids;
  
  /** The size of the aggregated results.
   * TODO - this is simply the size of the first series added. We need a way
   * to compute this properly.
   */
  private long size;
  
  /** The total number of raw data points in all series */
  private long raw_size;
  
  /** The data point overwritten each time through the iterator */
  private final MutableDataPoint dp;
  
  /** An index in the original {@link TimeSyncedIterator} iterator array */
  private int index;
  
  /**
   * Default ctor that simply sets up new objects for all internal fields.
   * TODO - lazily initialize the field to avoid unused objects
   */
  public ExpressionDataPoint() {
    metric_uids = new ByteSet();
    tags = new ByteMap<byte[]>();
    aggregated_tags = new ByteSet();
    tsuids = new HashSet<String>();
    dp = new MutableDataPoint();
  }
  
  /**
   * Ctor that sets up the meta data maps and initializes an empty dp
   * @param dps The data point to pull meta from
   */
  @SuppressWarnings("unchecked")
  public ExpressionDataPoint(final DataPoints dps) {
    metric_uids = new ByteSet();
    metric_uids.add(dps.metricUID());
    tags = dps.getTagUids() != null ? 
        (ByteMap<byte[]>) dps.getTagUids().clone() : new ByteMap<byte[]>();
    aggregated_tags = new ByteSet();
    if (dps.getAggregatedTagUids() != null) {
      for (final byte[] tagk : dps.getAggregatedTagUids()) {
        aggregated_tags.add(tagk);
      }
    }
    tsuids = new HashSet<String>(dps.getTSUIDs());